史前星球（2022）

They're running late.
象鸟们会在同一时期下蛋
Elephant birds synchronize their egg laying
好让所有雏鸟能够同时孵化
so the chicks hatch at the same time.
鸟群开启了迁徙之旅
The flock heads off together on a road trip.
它们体重一吨♥ 靠飞行赶路是不可能的
When you weigh one ton, flying isn't an option.
没有谁愿意被落下
No one likes to be left behind.
但这只小鸟就是不愿被催促
But this chick just won't be hurried.
其他鸟儿已经离开了
The others have already left,
前往它们夏季的湿地家园
heading for their summer home in the wetlands.
但它还站不稳
But she's still a bit wobbly on her feet.
在接下来的九个月里 它将完全依赖鸟爸爸的供养和保护
For the next nine months he'll be her sole provider and protector.
它们必须赶上队伍
They need to catch up with the convoy.
象鸟们结伴而行是有原因的
Elephant birds travel together for good reason.
因为森林里危机四伏
The forest is a dangerous place.
落单者最容易成为猎物
Stragglers are a prime target.
巨型马岛缟狸
Giant fossa.
一种伏击型掠食者 身手迅速而敏捷
An ambush predator, fast and agile.
现在不是解馋的时候
This is no time for a snack.
象鸟队已抵达目的地
The convoy has arrived at its destination.
这里再次下雨了
Rain has returned here…
创造出这片湿地
creating these wetlands…
为大家带来充足的水源和食物
with plenty of food and drink for all.
那落单的呢
But what about the stragglers?
就连最后一只孵化的小鸟也成功抵达
Even the very last chick to hatch has made it.
随着湿地扩大 象鸟的数量每年都在增长
As wetlands expand, their numbers are growing every year.
对象鸟来说 大融化是它们黄金时代的开始
The Big Melt is the start of a golden age for elephant birds.
但对于这只巨鹿来说 它的生存空间正渐渐逼仄
But for the giant stag, the world is closing in.
在森林中顶着3.6米宽的鹿角是个负担
In a forest, 12-foot antlers are a liability.
在下游 洞鬣狗们找到了渡河的地方
Downstream, the hyenas have found a place to cross.
大角鹿被困住了
Trapped.
一次奇迹般的逃生
A miraculous escape.
舍弃鹿角的它捡回了一命
Shedding his antlers saved him.
新鹿角将在下一个 繁殖期到来前重新生出来
A new set will grow for the next breeding season.
但对它的族群和洞鬣狗而言 所剩余的时间不多了
But the time for his kind and the hyenas is running out.
剑齿虎们已经跟踪猛犸象群两天了
The saber-toothed cats have been tracking the mammoth herd for two days.
它们的耐心得到了回报
Their patience has paid off.
那头公象
The male,
在剑齿虎首轮袭击中受了伤 如今掉队了
injured during the cats' first attack, has fallen behind.
它变得脆弱无助
He's vulnerable.
在猫科动物中 剑齿虎是个异类
In the cat world, her kind are unique.
它拥有狮子的力量
She has the power of a lion…
也拥有豹子的敏捷性
and the agility of a leopard.
剑齿虎们将得以再熬过一个冬天
The cats will survive another winter.
猛犸象群也是
The mammoth herd too.
但它们的世界正在改变
But their world is changing.
一个冰河时代诞生的新掠食者
A new predator born of the Ice Age
正逐渐分布至地球的每一个角落
is spreading to every corner of the planet.
而这个故事仍在继续
And that story is still unfolding.
巨型哺乳动物曾是冰河时代的霸主
Giant mammals ruled the Ice Age.
但几乎所有这些动物 都在大融化期间灭绝了
But almost all of them died out during the Big Melt.
真是太疯狂 也很不可思议
It's wild and super weird to think
曾经存在过的 所有巨型动物竟然完全消失了
that all the big animals that used to exist completely disappeared.
它们究竟遭遇了什么
What happened to them?
又为何会消失
And why?
（所有的巨兽都去哪了 ）
有个令人意想不到的地方 为这问题提供了答案
One surprising place has some answers.
洛杉矶
Los Angeles.
如果你来到洛杉矶 看到那纵横交错的高速公路网络
If you came to LA and saw the massive network of freeways,
你绝对想不到 这里竟拥有地球上最丰富的…
it would never occur to you this had one of the richest records
（副馆长 艾米丽林赛博士）
冰河时代遗迹之一
of the Ice Age anywhere on the planet.
就像是加强版的非洲大草原
Like the African savanna on steroids.
大多数人不会为了当 古生物学家而搬到洛杉矶
Most people don't move to LA to be paleontologists.
但我们当中有些人会这么做
But some of us do.
所以我会在这里啊
That's why I'm here.
艾米丽之所以会来这里 是因为一个特别的地方
Emily's here because of an extraordinary place.
它叫拉布雷亚沥青坑 是一个古老的沥青池
An ancient pool of tar called the La Brea Tar Pits.
拉布雷亚沥青坑 是全球最丰富的冰河时代化石遗址
La Brea Tar pits is the richest Ice Age fossil site in the world.
我们已经发现了近五百万件化石
We've found close to five million fossils
（洛杉矶的拉布雷亚沥青坑与博物馆）
而且几乎每天都还在挖掘出新的化石
and we are still excavating new ones almost every single day.
这些沥青池
These pools of tar
像陷阱一样 困住并保存了…
have acted as traps that have caught and preserved
所有走入其中的生物
anything living that has walked into them
积累下最为惊人的冰河时代生命记录
and built up the most incredible record of Ice Age life.
拉布雷亚拥有着 丰富到难以置信的化石记录
You have this unbelievably rich fossil record at La Brea.
这里出土的…
The number of bones
（进化生物学家 维多利亚赫里奇博士）
骨骸数量实在惊人
that have come out of this site is extraordinary.
我们发现了接近三千只剑齿虎的化石
We have probably close to 3,000 saber-toothed cats.
而恐狼则有五千只
5,000 dire wolves.
这里就像一座“阿♥拉♥丁的化石洞”
This is like an Aladdin's cave of fossils.
奇怪的是 化石记录突然中断了
What's odd is that the fossil record suddenly stops…
仿佛这些动物 一夜之间从地球上消失了一样
as if the animals just vanished off the face of the Earth.
我们能够对这些骨骸进行放射性碳定年
We are able to radiocarbon date the bone
从而精确地确定它们消失的时间
and pinpoint exactly when they disappeared.
令人惊讶的是 几乎所有这些物种
What was surprising was that almost all of these species
都在同一时间完全消失了
disappeared exactly the same moment in time.
它们都在一万三千年前 遭遇断崖式灭绝 之后便再也没出现过
They all hit this wall at 13,000 years ago and they never show up again.
那些曾经栖息着 冰河时代巨大动物群的广袤大地
Those vast landscapes teeming with herds of enormous
突然消失得无影无踪
Ice Age creatures and they're suddenly just gone.
这些动物的消失让我们不禁疑问
The disappearance of these animals makes us wonder,
“为何会如此突然 ”
"Why did this happen so suddenly?"
其中一个原因是 在冰河时代的末期
One reason was that the climate changed
气候变化得太快了
too fast at the end of the Ice Age.
加利福尼亚州在短短几千年内 气温就升高了5.5摄氏度
California warmed ten degrees in just a few thousand years.
一半的树木消失了
Half of the trees disappeared.
干旱一度持续了数十年
Droughts lasted for decades at a time.
有可能这些动物
It's possible that the animals
根本来不及适应如此快速的气候变化
were just simply not able to adapt fast enough to this changing climate.
但对拉布雷亚进行的 研究表明了事情并不止于此
But the work at La Brea shows something else was going on.
研究团队开始分♥析♥ 其附近湖泊的岩心样本
The team started looking at core samples from a nearby lake
以了解当时的环境发生了什么变化
to understand what was going on with the environment at this time.
而真正令人惊讶的是 其中炭的含量大幅上升了
And what's really surprising is there was a huge increase in charcoal.
一个新物种到来了
A new species had arrived.
伴随而来的是一种毁灭性的全新力量
And with it a devastating new force.
火是人类发明的最具威力的工具
Fire is the most powerful tool people have ever invented.
我们用火来做饭 照明 开垦狩猎的土地
We set fires to cook, to see at night, to clear land for hunting.
最早来到这片土地的人们 生活在一个随时可能引发大火的环境中
The first people to arrive in this area were living in a complete tinderbox.
人类带来了点火源
People brought in the ignition source.
数万年来
In tens of thousands of years
这里从未出现过如此频繁的火灾
there had never been any level of fire activity anywhere close to this.
这就像一颗被引爆的炸♥弹♥一样
It's like a bomb going off.
能够彻底摧毁环境…
That can completely decimate the environment
（气候科学家 艾拉吉尔伯特博士）
并给在那里生活的动物带来巨大威胁
and puts huge amounts of pressure on the animals that were living there.
目前尚不清楚这些火灾是人为还是意外
Whether the fires were intentional or accidental isn't known,
但它们摧毁了动物的栖息地
but they destroyed animal habitats.
再加上我们祖先们高超的狩猎技能
And combined with the hunting skills of our ancestors
这便成就了一场完美风暴
it was the perfect storm.
在整个地球上
Across the planet,
这种气候变化与人类活动的结合
this combination of climate change and human activity
几乎灭绝了所有冰河时代的巨兽
killed off almost all the Ice Age giants,
形成了我们今天所熟知的世界
leading to the world we know today.